Automotive signal light system



Dec. 30, 1952 YQUNG 2,623,935

AUTOMOTIVE SIGNAL LIGHT SYSTEM Filed March 16, 1949 quill- INVENTOR. THOMAS YOU/VG ATTORNEY switch case ?atented Dec. 30, 1952 UNITED STATES PATENT OFFICE AUTOMOTIVE SIGNAL LIGHT SYSTEM Thomas F. Young, Erlton, N. J., assignor to Arrow Safety Device Company, Mount Holly, N. J., a corporation of New Jersey Application March 16, 1949, Serial No. 81,669

2 Claims. 1

This invention relates to a control switch assembly and signal system employed for controlling turn and stop light signals such as are commonly used on motor vehicles. The switch assembly may be mounted on the steering column and operated by the driver providing a control for the signal lights and also providing an indication to the driver of improper operation of the signal system.

It is an object of this invention to provide a control switch of simple, economical and practical construction which may be mounted on the steering column of a motor vehicle and employed by the driver to control turn and stop lights.

Another object of the invention i to provide a pilot light which will indicate to the driver the existence of a failure in the signal system.

These and other objects of the invention will become apparent from the following description read in conjunction with the accompanying drawings, in which:

Figure l is an elevation of the switch assembly mounted on a steering column showing the case, the switch means and the mounting means in section;

Figure 2 is a plan view of the switch assembly with the switch case partly cut away showing the section taken on the plane indicated by the trace 2-2 inFigure 1;

Figure 3 is an end elevation of the switch assembly showing a vertical section taken on the plane indicated by the trace 3--3 in Figure l; and

Figure 4 is a diagrammatical showing of the electrical circuit employed in the present invention.

Referring to the figures there is shown a stamped metal switch case 4 to which is attached, by the use of four screws 6, a stamped metal bottom member 8. Afiixed to the bottom member 8 are the bracket members l8 supporting the switch assembly base plate 12. The base plate [2 is made of a resin impregnated fibre or other suitable. insulating material and provides a mounting plate for the switch parts as will be hereinafter described.

The switch case is mounted on the steering column [4 by means of the steel strap l6 which is passed around the steering column, through slots l8 in the channel member and is folded back in itself so that the ends l! of the strap lay over the strap l8 against the steering column. The member 22 is a box-like member having an open end 24 adjacent to the steering column 14. The edges 26 of the open end of the box are brought to bear firmly against the strap l6 and folded back ends I! by the action of the head of the screw 28. The screw 28 passes freely through the member 22 and the head of the screw rests upon member 22. The screw is threaded into the member 28. Thus, turning the screw draws the member 20 back into the box member 22 away from the steering column, pulling the strap tightly around the steering column, clamping the strap [6 and the ends thereof l'l firmly between the edges 26 of the box member 22 and the steering column thereby rigidly mounting the box member 22 against the steering column. The hole 29 in the side of member 22 is provided as a sight hole to facilitate the insertion of the screw 28 through the threaded bore in the member 20. After the member 22 is mounted to the steering column the switch case 4 is attached thereto by screws 39.

Riveted to the base plate l2 are the brass contact strips 44, 48, 48 and 58, the spring bracket 52 and the bracket 32. The bracket 32 is affixed to the base plate by rivets 34 and contains a centrally located bore 38 in alignment with the bore 40 in the switch assembly base plate l2. Rotatably mounted in the bores 38 and 48, as hereinafter described, is the switch shaft 42.

The uppermost portion 82 of the shaft 42 is of reduced diameter providing a mounting for the bracket 64 which rests on shoulder 65 and is held in position by the screw 86. The operating lever 88 is slidably mounted in the bore 10 in the shaft 42 and in the bore 12 in the turned down portion 86 of the bracket 84. The operating lever 68 passes through a slot in the switch case 4 and provides a handle for convenient operation of the switch. The screw 14 which is threaded through the bracket 84 bears against the lever 68 locking it in position, preventing it from being withdrawn from the bores l0 and I2. It will be evident that the rod may be moved inwardly or outwardly of the switch case within the limits provided between the shaft 42 and the turned down portion 82 of the bracket 84. Thus the end portion 84 of the operating lever 68, which is provided to be gripped by the operator, may be positioned to his convenience.

The turned down portion 86 of the bracket 64 is curved and forms a close oif plate back of the slot 80 in the switch case 4.

The insulating member 54 is made of a resin impregnated fibre or other suitable insulating material and contains a central bore which is pressed over the serrated portion 58 of the switch shaft 42 and bears against the shaft shoulder 43. The insulating member 54 is thus rigidly mounted to the switch shaft 42 and turns when the shaft the contacts 34, 46,

is rotated. Attached to the insulating member 54 by rivets 53 is the metal plate 55, which has contact finger extensions formed by diagonal bends, as shown at 56 and 51, and is made of brass or other suitably conductive material having spring qualities. The contact finger extension 55 bears against the stationary contact strip 34 and the finger 5! bears against the contact strips 46, 38 and 50 as the switch is moved to various operating positions. It will be evident that the diagonal bend in the contact finger provides a contact surface which slides somewhat sideways over the stationary contacts as the switch shaft is rotated, providing what is eifectively a wider sliding surface thereby reducing the wear and, yet, still retaining essentially the line contact which is the desirable construction for electrical contact surfaces.

The downward pressure provided by the bracket 32 bearing on the shoulder 6i) of the upper portion of the shaft 42 provides the necessary pressure to cause the contact flexible fingers 53 and 57 to bear firmly against the stationary contact plates 44, 46, 43 and 59. Also mounted in the shaft 42 is the pin I6 which rests in the notch 73 in the spring bracket 52 when the operating lever is in a central position as shown.

When the operating lever is moved to one side or the other of the central position the pin moves out of the notch 18 and bears against the upturned edge I9 of the spring bracket 52. There is thus provided an indication for the operator allowing him to feel when the switch is in a central position as well as a lock which holds the switch in the central position until it is forcibly moved therefrom by the operator applying pressure to the operating lever.

Riveted to the base plate I2 by the rivets 94 is the bracket 99 which retains the case 88 in which is mounted a flasher and relay assembly. The flasher and relay assembly may be of the type disclosed in the patent to Schmidinger 1,979,349 and provided with an auxiliary contact, or a similar flasher of suitable operating characteristics as will be hereinafter described. Extending outwardly from the base of the flasher case 88 are three connection lugs 9!, 92 and 93. In the interest of clarity, wiring has been omitted from the Figures 1, 2 and 3. The interconnection wiring of the switch assembly contacts and the flasher contact lugs will be evident from the electrical diagram shown in Figure 4.

Also riveted to the base plate I2 is the pilot light lamp socket SIS in which is mounted the pilot light lamp 9%). Mounted in the top of the switchcase directly above the pilot lamp 98 is the transparent jeweled element 99' which is so positioned as to be in the view of the operator.

Referring to Figure 4, showing the electrical circuit employed in the present invention, there is shown generally at I Ilil the wiring diagram of the control switch assembly, including within the outline 88, the flasher and relay assembly having the connection points SI, 92 and 93, and which will be hereinafter described in detail. Also included within the switch assembly is the pilot light 98 and the switch contact arm 55 and 48 and 59'.

The battery I 92, which is generally the battery included in the electrical system of the motor vehicle on which the signal system is installed, is grounded in the conventional fashion through conductor I93 toground I04, the other side of the'battery isconnected through lead'wire 4 I96, fuse member I08 and lead wire H0 to the connection point M of the flasher and relay assembly.

The signal lamp circuits include the front and rear right hand turn signal lights H2 and H4, respectively, the left hand front and rear turn signal lights IIS and I I8, respectively, the rear stop light I 28, and at I 22 a conventional stop light control switch which operates from the vehicle braking system. The flasher and relay assembly comprises an armature member I 24 around which is wound the armature coil I 33 and on which is mounted the movable contact arms I26 and I28. The flasher operation is controlled by the current limiting resistor I 36 and the thermal element I38 which are made of a high resistance heat resistant wire. The normal spring action of the flexible contact arm I26 urges the arm to move toward the armature and to contact the contact I34. The thermal element, however, extending between the arm I25 and the fixed point I37, holds the arm I25 away from the contact I34.

When a potential is applied across the connection points 9| and 92 a current will flow through the armature coil I39, resistance I35, thermal element I38 and through the arm I2 to the connection point 92. This current flow is limited by the current limiting resistor I36 to a value which will not produce sufiicient magnetic field to cause the flexible contact arm I28, which is held in open position by its own spring action, to be drawn against the armature I28. The current is sufficient, however, to heat the thermal element I38 which, upon heating expands, thus allowing the contact arm I23 to move inwardly gradually and, after a period of time, preestablished for the value of potential applied, to make contact with contact I34. When this contact is made the current flow will increase to a value determined by the capacity of the lamps in the circuit, and the increased current flow through the armature coil I39 will produce a sufiicient magnetic field to hold the contact arm I25 firmly against the armature I26 and also may, as will be hereinafter described, cause the contact arm I28 to close against the armature I24 and contact I32.

When the contact arm I23 engages contact I34 the high resistance I36 andthe thermal element I 38 are bypassed reducing the current through the thermal element to essentially a zero value, thus permitting the thermal element to cool and contract. When the tension developed in the thermal element by contraction therein is sufficient to overcome the magnetic effort of the armature field the movable arm I26 will be drawn away from the armature I 24 breaking the contact I 34. The current limiting resistor I36 and the thermal element I38 are thus again included in the circuit and another period of heating is begun during which time only a limited current will flow through the circuit. During this period of limited current flow the contact arm I23 will, by its own spring action, be drawn from the armature I24 and thecontact I32 will be open.

With the switch operating lever in the position shown in the figures the movable switch arm will be in the position connecting contact points 44 and 48, as shown in Figure 4. With the switch in this position an operation of the stop light switch I22, which will occur in a conventional fashion in conjunction with an operation of the vehicle braking system, will establish a circuit permitting current to'flow from the battery I02,

one side of which is grounded at I04, through the lead wire I06, fuse member I08, lead wire IIO, armature coil I30, current limiting resistor I33, thermal element I38, contact arm I26, lead wire I40, signal switch parts 44, 55 and 48, lead wire I42, stop light switch I22, lead wire I44, and stop light lamp I to the common ground I04.

Due to the high resistance of the path through the limiting resistor I and the thermal element I38, insufficient current will pass to illuminate the lamp I20. The current is suflicient, however, to heat the wire I30. The heat wire expands al.- lowing the contact arm I28 to move inwardly toward the armature I24 and to ultimately make contact with the contact point I34. When this contact is established the resistor I36 and the thermal element I38 are bypassed and a low resistance circuit is established through the flasher, and the current flow is dependent upon the resistance of the lamp member I20.

The current which fiows through the armature coil I30 when the lamp I20 is illuminated, creates a magnetic field in the armature I24 of sufficient intensity to close contact member I28 against the contact point I32 thereby closing the circuit between connection points 92 and 03 permitting current to flow from the battery I02 to contact point 92 as has been previously described and from connection 82 to connection point 83, through connecting wire I50, the lamp 88 and through wire I52 to the common ground I04.

As has been hereinbefore described, upon the closing of the contact arm I26 against contact point I34 substantially no current will flow through the resistance I30 and the thermal element I38. Thus, the thermal element will cool and contract and, when suificient tension has developed, will draw the contact arm I26 away from the armature I24 breaking the contact at I34 and again imposing into the circuit the resistance I36 and the thermal element I38 thus limiting the flow of current through the circuit to a value below that which is required to illuminate the lamp I20.

This reduced current value through coil I30 is immediately followed by a reduction in magnetic field whereupon the contact arm I28 will drop out, opening contact I32, interrupting the current through the pilot lamp. After a heating interval the thermal element I38 will again have expanded sufiiciently to allow the contact arm I26 to move inwardly making connection with contact I34 and the above described operation is repeated. Thus there exists a flasher system which, so long as a circuit is completed to ground, will continue to operate and if the current passing through the coil I30 is above the value required to create sufficient magnetic field to close the contact member I28 against its own spring tension, the member I28 will close and open in conjunction with the flashing operation of the flasher, thus causing the pilot light to blink simultaneously with the blinking of the signal lamp.

When the operating lever 68 is moved by the operator to a position to indicate, for example, a right hand turn the movable switch member 55 will assume the position 55, shown in construction lines, connecting the contact 44 with the contact 50. In this position of the signal switch, the current will flow from the battery I02 through the fuse I08 and the flasher assembly, as hereinbefore described, connecting wire I40, contact members 44, 55 and 50, the wire I54 and to the right hand front and rear signal lamps I I2 and H4, respectively, to the common ground I04. It will be evident that the turn lights I I2 and I I4 will cause a flasher signal to operate in a manner identical to that of stop light I20. However, it should be noted that when the signal switch member is in the position of contacting either contact member 50, in the case of a right-hand turn, or contact member 46, in the case of a left-hand turn, that a simultaneous operation of the stop light switch I22 will not cause a current to flow through a stop light I20 because of the fact that there is an opencircuit between contact members 44 and 48.

When the operating lever is moved to a position to indicate a left-hand turn the switch member will assume the position shown by 55", the left-hand turn lamps IIS and H8 will be energized and the system will operate as described above in connection with the right-hand turn lights.

The turn lights and the stop lights are selected to be of such capacity that the current flow through each of the three circuits will be approximately equal. For example, each of the turn lamps could be selected to draw three amperes and the stop light lamp selected to draw six amperes, or if two stop light lamps were employed they would be selected so that each one would draw three amperes. Thus, when operating under either the stop light load or the right-hand or left-hand turn signal load the flasher armature would be carrying six amperes when the contact I34 was closed, and only a small fraction of that value when the contact I34 was open and all the current in the circuit was passing through the current limiting resistor I36 and the thermal element I38. The spring tension of the contact arm I28 is adjusted, for use in a system having a normal six ampere load such as just described, so that six amperes through the armature coil would produce a sufficient magnetic field to draw the arm I28 against the armature and close the contact I32, thus causing the pilot light to blink in conjunction with the blinking of the stop or turn signal lamps. However, in the event of a failure of one of the signal lamps, the armature current would be reduced to three amperes and the spring tension of the contact arm I28 would be suflicient to prevent the magnetic field caused by the three ampere current from drawing the contact arm I28 against the armature and closing the contact I32. Therefore, the pilot light would not light and the operator would be aware of any failure in the system.

It should be particularly noted that in the present signal system the pilot light can operate only when the flasher contact I34 is closed and when the pilot light contact I32 is also closed. When the flasher is in a heating period the pilot light contact I32 is open, therefore, there is no common current through the flasher thermal element and the pilot light. Thus the operation of the flasher is entirely independent of the load imposed by the pilot light circuit.

It will be obvious that a relay having an armature coil similar to the coil I30 directly connected across connection points 0| and 92 may be employed in place of the flasher assembly shown affecting the omission of the flasher parts I25, I34, I36, I31 and I38. Such an apparatus would operate identically to the one described with the exception of the omission of the flashing feature.

What I claim and desire to protect by Letters Patent is:

1. A control switch assembly for use in an automotive signal lighting system having a pair of turn light signal circuits and a stop light signal circuit, said control switch assembly comprising a: manually operated switching means, three contacts adapted to be selectively engaged by said switching means, one of said three contacts being connected to the stop light s'ignalcircuit and the other two of said contacts each being connected to one of the turn light signal circuits, a pilot light, aflasher mechanism connected between a source of powerand said switching means, said flasher mechanism including a coil and contact means for repeatedly interrupting the flow of current from the current source to one of said signal circuits through said switching means, and a second contacting means associated with said flasher and connected between the source of power and said pilot light, said second contacting means maintaining an open circuit between the power source and said pilot light when said signal circuits are all disconnected from the power source by said switching means.

2. A control switch assembly for use in an automotive signal lighting system having a pair of turn light signal circuits and a stop light signal circuit, said control switch assembly comprising a switching means, said switching means including a'manually rotatable member, a contact leaf mounted on said member said leaf having one of its ends bent with respect to the plane'ofthe strip and on a line other than a line normal to the longitudinal axis of the strip, and three contacts adapted to be selectively engaged by the 8 bent end of said contact leaf, one of said three contacts being connected to the stop light signal circuit and the othertwo of said contacts each being connected to one of the turn light signal circuits, av pilot light, a flasher mechanism cann'ected between a source of power and said switching means, said flasher mechanism including a coil and contact means'for repeatedly interrupting the flow or current from the current source to one of said signal circuits through said switching means, and a second contacting means associated with said flasher and connected between the source of power and said pilot light, said second contacting means maintaining an open circuit between the power source and said pilot light when said signal circuits are all disconnected from the power source by said switching means.

THOMAS F. YOUNG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,005,963 Axelberg June 25, 1935 2,010,454 Haltrich et a1. Aug. 6, 1935 2,063,003 Curtiss Dec, 1, 1936 2,103,276 Schmidinger Dec. 28, 1937 2,141,210 Foulks Dec, 27, 1938 2,188,451 Bartens Jan. 30, 19 40 

